The invention relates generally to client-server computer networks. More specifically, the invention relates to a system and method for providing feedback to user input at a client system.
Typical computer networks include client systems that communicate with server systems over communication links. Often a user of the client system formulates and delivers queries to the server system through a user interface operating on the client system. The server system evaluates the queries and delivers responses to the client system for display on the client user interface.
Over the past decade, a wide variety of computer networks, such as local area networks (LANs), wide area networks (WANs), Intranets, and the Internet, have adopted remote application processing. In a remote application process system, all application program execution occurs on the server system, and only the control information for the client user interface, keystrokes, and mouse movements travel across the network. As a result, less resources of the client systems are needed to run applications.
A shortcoming of remote application processing, however, is that the client system may experience an unacceptable round-trip delay (i.e., latency) from when the client system sends input to the server system until the client system receives a response. Such delays can manifest themselves in remote computing environments, such as those encountered on the Internet, WANs, or satellite links, or with multi-user server systems. Regarding remote computing environments, the geographical separation of the client system from the server system produces the delay. This can be particularly troublesome to a user who is typing, for example, at the client system. The time required for the client input to travel to the server system and for the server response to return to the client system causes a palpable delay that can disconcert the user and induce typing errors. In multi-user server systems, the round-trip delay may depend more upon the ability of a busy server system, concurrently processing user interface data for multiple active clients, to respond to input received from a particular client system.
Consequently, the benefits of current remote computing and multi-user technologies are diminished for those implementations where the round-trip response time is greater than the acceptable user interface response time. Thus, a need exists for a system and a method that minimizes the delay sensed by the user of a client system in remote computing and multi-user computer system networks.
The invention features a method and an apparatus for reducing perceived visual response to user input at a client node that is remotely executing an application program on a server node wherein execution of the application program occurs on the server node. The client node transmits the user input to the server node, and the user input elicits a response from the server node that is transmitted back to the client node for display.
In one aspect, the invention features a method that comprises receiving user input to be transmitted to the server node. In response to the user input, a prediction of a server response to the user input is produced. This prediction is then displayed at the client node. The prediction can be determined based upon information about the applications currently running on the server. Relevant information includes cursor position, font, and other types of data.
In another aspect, the invention features a client node comprising an input device that provides user input to be transmitted to a server node, a processor that produces a prediction of a server response to the user input, and a display device that displays the prediction. The input device can be a keyboard or a pointing device.
In still another aspect, the invention features a client-server system comprising a server node and a client node. The client node includes an input device for providing user input, a processor, and a display device. The processor transmits the user input to the server node and produces, in response to the user input, a client response that attempts to anticipate a server response to the user input by the server node. The client response provides a visual response to the user input before the client node receives the server response. The displayed server response overwrites the prediction.